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(No Modei.) 3 Shasta-Sheet 1.

J. P. DAVIS.

UNDERGROUND SYSTEM FOR BLECTRIG- WIRES. No. 374,458. Patented Dec. 6,1887.

m Model.) 1' 3 Sheets-Sheet 2 J. P. DAVIS.

UNDERGROUND SYSTEM FOR ELECTRIC WIRES. No. 374,458. Patented Dec. 6,1887.

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JOSEPH I. DAVIS, OF NEW YORK, N. Y.

UNDERGROUND SYSTEM FOR ELECTRIC WIRES.

SPECIFICATION forming part of Letters Patent No. 374,458, dated December6, 1887.

Application filcdJuly 11,1857.

T aZZ 1071,0721, it may concern: I

Be it known that I, JOSEPH P. Dnvrs, of

' New York, in the county of New York and State of New York, haveinvented certain Improvements in Underground Systems for Electric Wires,of which the following is a specification. v I

i This invention relates to the construction of underground conduits andworkingchambers for the reception of electric wires; and it consists incertain improvements whereby an efficient, economical, and durableconduit can be made or built, and also in improvements in theconstruction and arrangements of theworking vaults or chambers and thecovers for the same, whereby they can he more efficiently andconveniently sealed to prevent the admission of moisture and securedagainst the ingress of unauthorized persons, while the manipulation ofthe said cover is by the use of suitable means facilitated. 7

It also consists in such a construction of the chamber-cover or man-holecasting as will dispense with the closing in or narrowing of thebrick-work of said chamber, thus producing a chamber which is much moreconvenient to work in than has heretofore been built.

It finally consists in the combination of the abovedetailed improvementsinto a harmonious system complete in itself. It is not necessary tostate specifically the object of this invention, since the said objectis sufficiently indicated, and is implied by the statement of invention.

I am well aware that it is old in the art to construct a conduit or aseries of parallel ducts for the reception of electric wires and toplace at suitable points at desirable distances from one anotherchambers into which the several ducts from different directions are led,the said chambers being adapted for the ingress of workmen and designedfor the purpose of connecting the several wires at junction-points, forthe testing of wires, and for other analogous manipulations, such anorganization having been shown, described, and claimed in Letters Patentof Great Britain issued December 22, 1854, to Felix Marie Baudouin, No.

Serial No. 243,998. (No model.)

In the drawings which illustrate and constitute a part of thisspecificatiomFigure 1 is a perspective view of the interior of one ofthe underground working-chambers illustrative of a special feature of mysystem. Fig. 1 is a general view, in longitudinal vertical section, ofsuch a sufficient portion of the system as is requisite forillustration. Fig. 2 is a vertical cross-section,and Fig. 3 a verticallongitudinal section, of the construction of conduit which I employ,extending subterraneously from chamber to chamber; and Figs. 3 and 3 areenlarged views of ajoint connecting two lengths of one of the pipes ortubes shown in Fig. 3. Fig. 4 is an enlarged view of one of theworking-chambers with conduits entering, showing more especially thespecial points of construction in the cover and chamber-top which Iregard asimprovements. Fig. 5isadetailshowing thesealing-gasket and theplan I adopt of holding the same in position. Fig. 6 is a detail showinga portion of the outer cover and showing means for the ready raising ofthe said cover. Figs..7 and 8 show perspective and sectional views ofthe means for securing the closing-bar of the inner cover. Fig. 9 is asectional elevation of a vault, illustrating a modified form ofcover-casting, whereby I am enabled to maintain ample room for workabove the brick-work line and to dispense with closing the brick-work inat the top. Fig. 10 is a detail of the inner cover, showing in plan oneof the lifting-handles therefor.

I will describe, first, the general construction of the system ofconduit and working vaults, referring to Figs. 1, 2, 3, 8, 3 and 9, andwill afterward describe the details which appear to require specialconsideration.

I construct the conduit-sections of hydrauliccement pipes, each providedwith an envelope of sheet-iron riveted longitudinally, as shown at 18,Fig. 3", and having cast-iron joint-pieces and 14, Fig. 3, on the ends,(male and female,) over which joints are placed a sheetiron collar, awire-netting, or a base-work con sisting of a sheet of textile fabric,which is filled with cement, 17, so as to make a perfect joint.hydraulic cement concrete, which is thoroughly treated with hot asphalt,and the entire mass of cement pipes and the concrete matrix constitutes,in fact, a continuous mass These pipes are deposited in layers in,

from each chamber to the next, the ends of each conduit beingsubstantially flush with the inner surface of the chamber-walls.

The individual ducts 4 are made, as hereinb'efore stated, of sheetironlined with hydraulic cement, and in'practice are from two and onehalf tothree inches in inside diameter, with a thickness in the cementlining 12offive-eighths of an inch, and the thickness of the sheet-iron envelope13 is conveniently No. 24 to No. 26 gage.

At the ends of each pipe-section is fitted a cast'iron jointing-piece,14 and 15, male at one end and female at the other, whereby the bore ismade continuous throughout the entire sect-ion. During the process oflaying I use a sheet-iron collar or sleeve, 16, riveted on a seam, 19,Fig. 3", or alternatively a piece of fine wire-netting attached to thepipes over thejoint with strong wires, so as to hold the ends of thepipe immovable. Either of these jointenvelopes is then filled in withpure cement concrete, which is thus caused to com pletely surround thejoint and to closely ad here to the same, producing apracticallyhomogeneous length of duct; or in place of either I mayspread the cement on a sheet of suitable textile fabric-such as linen,cloth, or canvas-and apply the same to the outside of the joint to forma complete conduit. The method adopted is to dig a trench of suitabledepth, and after well ramming the bottom of the same to apply thereupon,first, a layer of the cement concrete, then a horizontal layer ofpipes,jointingthepipesas they arelaid,ashereinbefore described. Concreteis then rammed in between and over them to the required thickness, afterwhich another layer of pipes is laid, and so on until the entire conduitis built up.

It is in many cases advisable to employ an external box, 2, in which tolay the conduit, as indicated in Figs. 2 and 3. This forms a compactbottom and lining for the trench, and serves as a form for the concretemass containing and surrounding pipes. Where such a box is used, it maybe made of rough spruce or hemlock of one to one and one-fourth inchthick. Before laying the concrete mass therein the inside of the boxbottom and sides are well swabbed with hot asphalt, so that the concretewhen put in sets against the waterproof coating. When completed, the topof the mass is coated with asphalt, also, before filling in the trench.used, it is only practicable to swab or'paint the top of the concretewith the hot asphalt, which will sink into the material and aid inpreventing moisture in settling in from the top. It is well beforepainting with the asphalt to round off or arch the top of the concrete,as indicated at B, Fig. 2; but, if desired, the

V conduit may be covered with a rough plank.

This, however, is not absolutely necessary.

The Vault or working-chamber is, as indicated in Figs. 1, 4-, and 9,usually constructed of masonry, and has vertical walls with suit- If nowooden box be.

able openings in their sides for receiving the ends of theconduits. Theseveral conduits are connected at suitable intervals by theseworking-chambers, which are used for jointing, testing, and othernecessary manipulations, and for convenience in the work of drawingwires or cables through the conduits from chamber to chamber. In thefloor of the said chambers are embedded ring-bolts 76 and 77, withinwhich is placed, during the process of drawing in, an iron bar, 78. Thisbar may of course, as circumstances shall re quire, be inserted eitherin the rings 76 or 77, which are arranged transversely with one another.snatch-block, 79, round which passes the rope 81, whereby the cables orconductors may be drawn through the conduit from one workingchamber tothe next. In the drawings the rope is represented as being used to haula cable through the duct 4 of the conduit B at the right side of thevault, the rope passing round the snatch-block and through the manhole,and the power being applied thereto on the outside.

B is the end of a conduit entering from an-' other direction, and cablesare shown as entering from both directions and led round the sides ofthe vault to other conduits.

In the mouth 1 of the vault may be seen the man-hole casting, showingthe recess 5 of the locking-bar.

Such a construction as is described presents numerous advantages. Usedwith a single envelope of sheet-iron having just thickness enough toprotect the pure cement lining in transportation and handling until itis safely embedded in the hydraulic-cement concrete, it reduces themetal to a minimum, with corresponding electrical advantage, and gives aconduit consisting of a series of pure cement ducts, and affording anexcellentsmooth hard surface for the drawing in and out of cables,composed, moreover, ot'an imperishable material, the value of whichincreases with time. The cement free from moistureis a goodnoneonductor, and surrounded as is each duct by a thin metal envelope,thoroughly asphalted, the duct can be quite safely relied upon to beimpervious to water or gas except at the joints of the pipesections. Atthese points the male and female joint-castings, arranged ashereinbefore described, produce a tight fit; and when the pipe andjointsare embedded in a matrix of hydraulic-cement concrete asphalted hot onthe sides of the mass the construction will be a strong, tight, anddurable one.

I will now describe the man-hole castings and the special arrangementsand devices associated therewith which I have devised.

The man-hole casting or working-vault cover used for vaults of ordinarysize (that is, say, four feet cross-section) is illustrated in Figs. 1and 4. It comprises a circular cast-iron frame, D, ribbed for strengthand resting by a broad flange, (1, upon the brick-work of thevault-walls below the surface of the earth, an

In either case it forms a support for a upper or'outer street-cover, O,substantially flush with the surface of the street and resting upon aflange or recess, 0, in the mouth 1 of the frame, an internal or sealingcover, F, resting on a projecting rim or upturned flange, 6, extendingfrom the. inner surface of the said frame, and a locking-bar, E, andattachments therefor. As shown more clearly in Fig. 5, the flange 6projects inwardly from the lower edge of the frame on the samehorizontal plane 'as the broad flange d and sweeps upward with joint ofthe upper cover. Any water which does get in flows over the sides of thecover to the annular trough 8, formed by the supporting-ring, fromwhence it may be carried off by a pipe, 0, leading through the masonryto the surrounding sand or earth, the upper endof the said pipe beinglet into the bottom of the trough. The sealing-cover also is made with araised rim, r, round it, forming a circular guide when it descends intoplace, and this rim, after extending upwardly, takes a downward curve,so as to form a recess, 10, into which fits a circulargasket or ring,11, of india-rubber pipe.

Heretofore the gasket in man-hole castings has been allowed to lie freeon an open flat or horizontal flange, or it has rested in a groove in aflanged support under the street-cover, or has been placed in a widerecess in the cover, beveled in both directions, so as to facilitatefinding and fitting the cover upon the lower or seating flange. All ofthese forms of construction are liable to the same objectionnamely, thedifficulty and well-nigh impossibility of maintaining the gasket in aproper position to provide a constant and positive fit where it canfully perform its function. More over, in none of these forms ofapplying the gasket, so far as I am aware, has there been employed atubular gasket which has the special advantage of elasticity.

In the construction which I have devised only gaskets with holes throughthem (such as pipe) should be used on account of the high degree ofelasticity possessed by them when of such a construction. The gasket 11is moreover made to fit tightlyin the recess, the crosssection of whichis in shape that of an arc of a circle of a proportion greater than thatof a semicircle; I have found a two-thirds are satisfactory. Under theseconditions the gasket once pressed into the circular recess has notendency to drop out or become misplaced, but is held in position, sothat at all times, when the cover descends in place, the gasket receiveson its entire circumference the upward pressure of the projecting rimand makes a tight joint. Inasmuch as the gasket is made of elastic pipeor tubing, this positive hold or grip still leaves full play to thesealing action .due to the upward pressure of the flange, thusconstituting in practice a considerable improvement on any previousconstruction.

Heretofore, so far as my knowledge extends, both internal and externalcovers have had to be pried up and raised with a crow-bara mostinconvenient operation. By reference to Figs. 4, 5, and 10, it will beseen that I obviate this inconvenience with respect to the inner coverby attaching a handle, it, to the lugsj and j at two opposite pointsnear the edge of the said cover, whereby it may be readily and easilyraised when required.

Referring now to Figs. 4, 7, and 8, I will describe the means adoptedfor maintaining the requisite pressure on the sealing'cover. This iseffected by combining the use of a cross bar, E, ascrew-bolt, X, and apadlock,

f, therefor in a mode which I shall now describe. The cross-bar E, whichis of wroughtiron, has a threaded hole at its center,through which thebolt Xis screwed, the said boltfinding a bearing and centering in asmall recess, m,in the cover. When the bolt'is screwed up, the ends ofthe bar arelet into recesses formed by lugs 5 in the sides of theman-hole casting, and there find a counter-bearing, as shown in Fig. 4.The screw-bolt has a flattened head, 9, with an eye, 0, drilledthroughit. The flattened part of the bolt, when screwed down snug, risesabove the upper surface ofthe crossbar, and when the flattened sides ofthe bolt are at right angles to the sides of the cross-bar, asin Fig. 8,an iron saddle-piece, a, having a rectangular slot, 2', cut througlrit,is let down over the rectangular head of the bolt, which passes throughthe slot so that it straddles the bar. A padlock, f, is then attached tothe bolt X, the hasp passing through the eye thereof. Vhen this is done,the screw-bolt cannot be unscrewed to allow the bar to be removed andthe sealingcover lifted, giving access to the manhole to unauthorizedpersons, except by breaking the padlock or other part of the closingdevice, (which constitutes a burglarious act,) because as long as thesaddle re mains astride of the bolt and bar the turning of the bolt isprevented by the sides of the saddle impinging against the sides of thecrossbar. The outer cover, 0, is, when in place, flush with the surfaceof the ground,and does not in form differ from the form usuallyemployed. It may, however, at one or more points of its periphery beprovided with a recess or notch, a, wherein a suitable bar or tool maybe entered to raise it up.

Instances frequently occur where a large wide conduit or a number ofseparate conduits, B, Fig. 9, must gain entrance with their numerousductsinto' a subterraneons workingchamber, but near the streetsurface.In

such cases a vault, A, of unusuallylarge size, is essential, and it isfound convenient to increase the cross-section to five feet in order toaccommodate the increased number of ducts.

The side walls of the working-vault being so far apart, itis found thatin order to use the man-hole frame hereinbefore described, andillustrated in Fig. 4c, the masonry would require to be drawn in fromabout three feet below the surface for the purpose of contracting itsmouth to the proper size to be surmounted by the said frame, which isintended for the or dinary vault, having a width,usually, of about fourfeet; but to so contract or narrow in the brick-work at the top of thevault is inconvenient in construction and circumscribes the head-room orworking-space. I have therefore devised an extension frame, G, as inFig. 9, underlying the upper frame, D, to which it is bolted, andresting upon the top of the brick-work, into which a vertical flange,it, enters to prevent the ingress of water. Thus the entire advantage ofthe increased width of the vault is utilized, the headroom-is enlarged,and the conduits near the street-surface are enabled to enter. It is notessential to furnish this construction with the drain-pipe 0, lead ingbelow the lower frame into the surrounding earth, as the drain may becaused to pass through thejoint between the castings at I I have notdescribed the introduction of electric cables or wires into theseconduits, and it is to be understood that anyof the wellknown cables maybe introduced by any of the ordinary modes.

Having now described my invention, I claim- 1. The combination, in aman-hole frame or crownpiece for subterranean vaults or workingchambers,of a circular frame having a flat base-plate or flange resting on thevault-masonry, an internal or sealing cover therefor having a curvedflange or rim incasing permanently and adapted to tightly grip anelastic gasket of rubber tubing or analogous material, and constitutingalso a guide for the cover, an upwardly-curved flange projecting fromthe inner wall of the circular frame and forming an annular channel toreceive waste water, and serving also as a seat for the coverilange andgasket, and a waste-pipe leading from the said channel downward andthrough the masonry, as described herein.

2. The combination, substantially as described, in a manhole-framecasting, of the annular channel 8 for waste water, having the curved andupturned flange 6, the inner or sealing cover F, with the upturned edge1' and flange curved on itself, so as to form the recess center, athreaded eyebolt with flattened head adapted to engage with the threadedhole in said bar and to center in and bear upon the step on the cover,the slotted saddle adapted to be slipped over the said eyebolt when thelatter is screwed home and to bestride the bar, and a padlock forattachment to the said eyebolt, all in combination and cooperating asdescribed.

4. The combination, with a working chamber or vault built withapproximately-vertical walls of masonry, of an extension-frame therefor,the said frame being provided with ribbed flanges resting upon the topof the vault-walls, and provided also with a horizontal flange at itsupper side, which flange curves upward at its inner edge, and asurmounting frame pro vided, as hereinbefore described, with the innerand outer covers and their locking devices, which surmounting framerests upon the horizontal flange of the extension or base frame,surrounding the inner upwardly-curved edge thereof, as shown, thusconstituting an annular canal for waste water and affording a construction giving a greatly-increased head-space, dispensing with thenecessity of contracting the masonry, and adjusting an uppermanhole-frame of standard size to an enlarged square section of vault,substantially as described.

5. Theeon1bination,\vitl1theworking-chamber in an underground system ofconduits, of pairs of ring-bolts fixed in the floor parallel to therespective walls thereof or opposite the conduit ends, and asnatch-block bar adapted to be inserted in the two ring-bolts of a pair,for the purposes specified.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, this 29th day of June, 1887.

.IOS. I. DAVIS.

Witnesses:

'Trios. D. LOCKWOOD, A. J. WAGNER.

